CVE-2001-0137 in Windows Media Player
Summary
by MITRE
Windows Media Player 7 allows remote attackers to execute malicious Java applets in Internet Explorer clients by enclosing the applet in a skin file named skin.wmz, then referencing that skin in the codebase parameter to an applet tag, aka the Windows Media Player Skins File Download" vulnerability.
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Analysis
by VulDB Data Team • 04/11/2025
The vulnerability identified as CVE-2001-0137 represents a critical security flaw in Windows Media Player 7 that demonstrates the dangerous intersection of media player functionality and web browser exploitation techniques. This vulnerability specifically targets the way Windows Media Player handles skin files, particularly those with the .wmz extension, which are essentially compressed archive files containing skin elements and associated code. The flaw enables remote attackers to deliver malicious Java applets directly to Internet Explorer clients through a carefully crafted skin file that exploits the player's automatic download and execution mechanisms. The vulnerability operates by leveraging the codebase parameter within applet tags to reference the malicious skin file, which then gets processed by the Windows Media Player component and subsequently executed within the Internet Explorer context.
The technical implementation of this vulnerability stems from Windows Media Player's improper handling of skin files that contain embedded Java applets. When a user encounters a webpage containing an applet tag that references a skin.wmz file, the Windows Media Player component automatically downloads and processes the skin file without adequate security validation. This behavior creates a pathway for attackers to execute arbitrary code on vulnerable systems, as the skin file can contain malicious Java applets that are then executed within the context of the user's browser session. The vulnerability specifically affects Windows Media Player 7 and represents a classic example of how multimedia components can become attack vectors when they interact with web browser security models. The flaw resides in the lack of proper input validation and security boundary enforcement between the media player component and the web browser environment, creating a dangerous execution path that bypasses normal browser security restrictions.
The operational impact of CVE-2001-0137 extends far beyond simple code execution, as it provides attackers with a sophisticated method for delivering malware and conducting various cyber attacks. This vulnerability enables threat actors to perform remote code execution on vulnerable systems, potentially leading to complete system compromise and persistent access. The attack vector is particularly insidious because it can be delivered through legitimate web browsing activities, making it difficult for users to distinguish between benign and malicious content. The vulnerability can be exploited to download and execute additional malware components, establish backdoors, or perform other malicious activities that would otherwise require more complex attack vectors. From a security perspective, this vulnerability represents a significant risk to enterprise environments where users regularly browse the internet and interact with multimedia content, as it can be exploited through simple web page visits without requiring any special privileges or user interaction beyond normal browsing behavior.
Security professionals should note that this vulnerability aligns with CWE-749, which describes the exposure of a remote code execution vulnerability through the improper handling of untrusted data. The flaw also corresponds to techniques described in the MITRE ATT&CK framework under the T1059.007 sub-technique for 'Command and Scripting Interpreter: PowerShell' and broader categories related to 'Exploitation for Client Execution' and 'Phishing with Spoofed Email'. Organizations should implement immediate mitigations including disabling automatic execution of Java applets in Internet Explorer, updating Windows Media Player to versions that address this vulnerability, and implementing network-level controls to block access to potentially malicious skin files. The vulnerability highlights the importance of maintaining up-to-date security patches and demonstrates how multimedia components can serve as attack surfaces that require careful security consideration. Additionally, users should be educated about the risks of visiting untrusted websites and the importance of keeping their software updated to prevent exploitation of known vulnerabilities.